0007229: Only the first midi "Transform" tool field is updated when changing the property combobox

Description

On a MIDI region, using the right click > Region name > MIDI > Transform... tool, changing the property dropbox (Velocity, Length...) updates the first set of fields but not the subsequent ones added with the "+" button.
The result is, e.g. setting the property to start time, one can only add an integer between 1 and 127 when using e.g. "exactly".
The added operations fields should update as does the first operation ones, so that a property accepting decimal values would update the susbsequent operations fields to allow for decimal values.

Steps To Reproduce

- Right click on a MIDI region, Region name> MIDI > Transform...
- Add an operation by clicking the "+" button
- change the newly created operand to "a random number between"
- change the initial property to "start time"
=> the newly created fields show "1 to 127" (integers only)

- change the first operand to "a random number between"
=> the first line fields correctly show "1.00 to 127.00" (decimals allowed)